An Overview of Biostimulants’ Effects in Saline Soils

Abstract

The unsustainable use of natural resources and their overexploitation continue to be major threats to global agriculture development. This practice increases the abiotic stresses, resulting both in crop yield losses and soil degradation. Low productivity is often associated with salinized soil, which is caused by the toxic and osmotic effects of soluble salt accumulation and, consequently, lack of organic matter. Conversely, there is a need to improve the current crop productivity to meet the increasing food demands. Among the current methodologies proposed to increase plant resistance to abiotic stress, the utilization in crop production of plant biostimulants has been recently proposed. These are organic products mainly based on algae, microorganisms, fulvic and humic acids, proteins, and amino acids that improve physiological plant performance, leading to increased crop productivity. Among their positive benefits, the application of plant biostimulants can also reduce the usage of conventional chemical fertilizers. The aim of this work was to present the effects of different biostimulants on saline conditions. In particular, in this review, we report and critically discuss the most recent research dealing with the effects of the application of plant biostimulants both on crop growth and on plant salinity resistance.

Selected Beneficial Microbes Alleviate Salinity Stress in Hydroponic Lettuce and Pak Choi

“…Existing research on microbes in soil-based production systems supported that PGPMs alleviated salinity stress by improving plant responses (e.g., improved nutrient uptake, root development, and shoot biomass accumulation) rather than mitigating the salinity levels in the soil environment (Egamberdieva and Lugtenberg 2014). Mechanisms behind those improvements in plant responses can be summarized as follows: 1) increased nutrient availability and uptake due to extraradical hyphae; 2) induced plant systematic resistance to stress by promoting the production of phytohormones (e.g., auxin) and osmolytes (e.g., sugars, amino acids) to overcome osmotic stress; and 3) activating antioxidant systems to scavenge reactive oxygen species (ROS) (Egamberdieva and Lugtenberg 2014; Gupta et al 2021;Lakhdar et al 2023). Our results further extended the potential use of PGPMs, particularly Glomus mycorrhizal fungi, to improve lettuce growth and B/P/T mix to increase pak choi growth in hydroponics.…”

“…Even though water can be treated to remedy high salt concentrations, it is extremely expensive. Lack of proper soil management combined with other environmental concerns has resulted in issues like salinity negatively affecting populations of beneficial microbes in both conventional and organic agroecosystems (Lakhdar et al 2023). Furthermore, the presence of strong microbial communities in symbiosis with plants can be enough to help each persist under stressful conditions.…”

Microbiological Biostimulants in the Improvement of Extended Storage Quality of In Vitro-Derived Plants of Popular Ornamental Perennials

“…phosphates, and suppress plant pathogens, contributing to improved nutrient uptake, disease resistance, and overall plant vigor [21]. Additionally, microbiological preparations play a significant role in soil remediation and bioremediation by breaking down pollutants and toxins, thus aiding in environmental sustainability [22]. However, to date, little attention has been paid to the use of microbiological preparations in the production of ornamental perennials.…”

Recent Advancements in Mitigating Abiotic Stresses in Crops

“…Higher plant extracts are also used as potential alternatives to chemical fertilizers in alleviating abiotic stresses by regulating physiological processes and enhancing productivity in crops. Various parts of these plants, including the seeds, roots, stems, leaves, bark, and flowers, are used [221]. The plants used for biostimulants are rich in phytohormones, antioxidants, minerals, amino acids, and many other bioactive compounds with nutritional and growth-promoting potential [222].…”